Vehicle tire water spray control system

ABSTRACT

A vehicle spray control system apparatus and method for suppressing spray and coalescing and directing water droplets thrown from rotating tires of vehicles via centrifugal forces comprises various embodiments of spray controllers adapted for selective locations on vehicles, such as large commercial trucks and tractor-trailer combinations. The preferred embodiments are used as: fender flap, between tractor-tandem, over-wheel, floor sill, and general purpose spray controllers, located where droplets impact at high velocity and side skirts to condense low-velocity mist and carry the water rearward. Embodiments have a receiving side and an opposite side and comprise a plurality of symmetric or asymmetric wedges which extend from the planar surface of and are integrally formed with a base. In respective embodiments, these wedges either touch or are closely spaced apart at the receiving side of an unperforated base, or a base having slots. When used, a plurality of straight slots or slanted slots, respectively, pass either perpendicular to or at an angle through the base in respective embodiments. The spray controllers are formed from flexible or rigid durable materials such as high or low density polyethylene or rubber to resist summer heat, winter cold, impact, abrasion and chemicals, without softening or breaking. Flexible side skirts with longitudinal ridges or wedges having near horizontal upper surfaces extending toward the overwheel mist are also preferred embodiments.

CROSS REFERENCES

This application is the third continuation in part application filedwhile the second continuation in part application Ser. No. 07/200,837,filed June 1, 1988, and now abandoned was still pending. The first andsecond continuation in part applications were determined to beconsidered as copending with the original application Ser. No.06/509,875, filed July 1, 1983 and now abandoned. All three of theseapplications have the same title Vehicle Tire Water Spray ControlSystem, and George E. Metcalf is the Applicant of all threeapplications.

BACKGROUND OF THE INVENTION

Water droplets of spray or "tread throw", hereinafter referred to as"throw" are thrown from rotating tires of vehicles traveling on wet roadsurfaces and impact against surfaces of the vehicle, causing the spraydroplets to fragment into smaller droplets of mist. This presents theproblem of impaired visibility to the drivers of these and othervehicles during wet conditions. Water thrown from the tires generallycomprises large and small water droplets, some in the form of a mist oreven a fog. Tests have demonstrated erratic directional control bydrivers of following cars and trucks which are enveloped in this mist,especially that from large commercial trucks and tractor-trailercombinations which are moving ahead of them or beside them as theytravel on the wet roadways. Drivers of these large vehicles also havedifficulty seeing, via their rear view mirrors, through the spraygenerated by their own vehicles which occasionally causes accidents asthese vehicles change lanes.

Several devices and apparatus for controlling road spray have beendeveloped to reduce the impaired visibility for these drivers. Forexample, F. D. Roberts, in his U.S. Pat. No. 3,341,222 discloses aVehicle Wheel Spray Collector which has alternate upward and downwardflaring channels with slots spaced apart and located at the top of theupward flaring channels. These channels when arranged in the shape of afender, collect water from the spray in the bottom of the downwardflaring channels, which is thrown from the tires through the slots atthe top of the upward flaring channels. A trough at the bottom of thecollector collects the water and deposits it outside the tracks of thetires of the vehicle. The function of Roberts' invention is to collectthe throw droplets rather than to directly coalesce, directly suppress,or direct the throw. Roberts' spacing and size of the slots in thechannels and the excessive height of his corrugations, which areconsidered to be his wedges, permit spray to fall back onto the rotatingtire beneath the collector to spray again.

Brandon et al. in their U.S. Pat. No. 4,258,929 disclose a Vehicle SprayReduction Apparatus utilizing an unperforated mud flap having V's facingthe throw above and behind tires and troughs behind the V's to carry thewater rearward above the tires and to protect the downward flow behindthe tires.

Reddaway in his U.S. Pat. No. 3,899,192 presents a Fender Flap SprayController which uses an artificial turf surface to collect the spray,wherein the water flows down behind the surface matting of the fenderflap and is channeled away from the tires.

Roberts et al. in their U.S. Pat. No. 4,205,861 disclose an AutomotiveVehicle Wheel Spray Collector, utilizing Roberts' earlier flaringchannel design of his U.S. Pat. No. 3,341,222 in which flanges besidethe slots and a ridge in the formerly flat backing is now used behindthe channels and slots to deflect the spray droplets into the bottom ofthe downward flaring channels, within the water collecting tank beyondthe channels. His wedges are too high and therefore some water flowingalong them at an angle slows down, stops and falls back upon the tiresto create more spray rather than entering the slots.

Irving in British Patent No. 1,584,453 discloses Improvements in MudFlaps similar to Roberts' flaring fender, in which one or two layers ofopen-ended channel members guide spray into a containment region, inwhich it coalesces to form water which runs down in vertical V's and isdeposited on the pavement near the center of the trailer.

Other fender flap designs such as the rubber button flaps made byNational Rubber Company, also made by Buxbaum Company and also made byKonetta Company, are designed to suppress formation of mist from thehigh speed throw from tires. The Konetta spray control system is thesystem described by Lightle, et al. in their patent 4,382,606 of 1983.Lightle describes the function of these ribs and of those on the "splashguard" behind the wheel as "flow control" to direct the condensed waterto flow in the desired direction. They have little to do withcondensation and coalescence which are accomplished by the vertical wallof the skirt and the buttons or cones on the splash guard. The tendegree slope of the ribs simply eases removal from the mold. The ribswere neither intended to nor are they capable of suppressing speedthrow. They use side skirts with vertical ridges separatedlongitudinally by 1 1/2 inches to coalesce the water and to direct it todrain vertically downwardly thus preventing the rearward flow valued byside skirts of this invention which have horizontal wedges or ridges thedistance between upper surfaces being between 1/2 and 2 inches.

In Heinz-Henning Jurges' U.S. Pat. No. 4,427,208 of 1984, his mudguardis used to prevent spray generated over, behind and ahead of the wheelfrom travelling laterally. Rather, it lets the water fall back upon thetire to spray again. Jurges' ribs or wedges are widely spaced apart anddecrease in height as they approach the outer edge, continuing down thesplash protector edge outside the wheel. These ribs or wedges will notcarry water to fall near a splash guard because they are too small inprofile and have a 50 degree symmetric vertex angle. In addition thedownward slope of the fender and the air motion forward of the wheelblow the water back onto the tire in a crosswind and prevent these ribsfrom functioning as do the horizontal ribs and wedges of this invention.

Maurice Goodall, in his U.S. Pat. No. 4,290,609 of 1981 disclosesgutters to carry collected water. His design does not include wedges,but provides screens for spray control. His screens are complex anddifficult to clean, contrasting with the open ridges and wedges of thisinvention. He uses ram air rather than normal air flow to force thewater rearward. His screens will quickly fill with dirt and ice and arenot selfcleaning.

Pete A. Schons in his U.S. Pat. No. 3,834,732 of 1974 discloses a spraycollector like Roberts' spray collector. Removing Schons' openings wouldprevent spray control.

Thaddeus M. Ochs in his U.S. Pat. No. 3,473,825 of 1979 shows anddescribes stiffeners that run down both edges of the flap to preventlifting and twisting, thereby holding this fender flap in position inthe presence of the high speed air flow.

Harold V. Conner in his U.S. Pat. No. 3,877,722 of Apr. 15, 1975describes a vertical stiffener attached to the fender flap and to rigidcross members at top and bottom to reduce twist and lift.

Ross A. McKenzie and Hans Busch in their U.S. Pat. No. 4,398,734 of1983, include an overwheel splash guard with a solid base and rubbernipples facing downward, which permit the coalesced overwheel water tofall on the tire to make more spray. Also they provide a fender flapspray controller with rows of rubber buttons facing the spray. Theserubber buttons suppress the spray and collect water that flows betweenthe rows of rubber buttons, to ultimately fall to the surface below.

James E. Clutter in his U.S. Pat. No. 4,436,319 of 1984 uses a tankshaped like a fender having inner and outer walls separated by about oneinch, similar to Roberts' fender, except that he uses laterallyextending flanges around the periphery and flanges extending in thedirection of rotation in the side portions to guide the throw into thetank. The water flow is not along the flanges, but transverse to them,the flanges deflecting the water into the tank from which it is drainedto fall outside the paths of the tires. The flange openings and interiorof the tank are not self-cleaning. The system ceases to function whenfilled with dirt and is very difficult to clean, except the exteriorfender-like surfaces.

Fritz Buchner, in her German patent, reference DE 3635854 dated Oct. 22,1986, shows an alternate method to trap the upward moving throw behindsingle axles. He has a forwardly and downwardly extending top portion ofhis fender flap which deflects the upwardly moving throw rearward tofall along the forward surface of the vertical part of his fender flap.

Although these specific prior advances have been made to try to controlmist or spray, a significant improvement in visibility has not as yetbeen successfully accomplished by these earlier inventions as stated bythe U.S. Department of Transportation in April 1988.

In reference to the history of these earlier inventions, the simple,flat fender flaps, also called mud guards, splash guards, or mud flaps,originally were hung behind rear tires to prevent mud from being thrownfrom roads onto following vehicles' windshields. Then fenders were usedto improve the containment of mist, spray, and mud. However, with modernhigh speed travel on paved roadways, even widely separated ribs do notadequately suppress spray formation in fender flap or overwheellocations and narrow ribs alongside cannot carry the water to the fenderflap location. Curved fender like wedge arrays with slots leading tocontainment regions are ineffective if the wedges are too high, therebyrequiring condensed water from the throw, impacting at large angles fromthe radial direction, to flow too far along the wedge surface beforeentering the slots, flanged or otherwise, thereby allowing friction tostop it and it falls on the speeding tire to become copius spray.

It appears that earlier inventors did not achieve the savings andeffectiveness of these simple flat arrays with low wedges for severalreasons, such as their lack of awareness of:

the importance of keeping the angle of impact for overwheel slottedarrays near normal to the array;

the importance of using wedges having heights small enough to utilizethe slots effectively, but large enough to effectively suppress mistformation;

the importance in reference to slotted arrays with straight slots, thatis, slots perpendicular to the base, that the slots be deep enough inthe direction of motion of the throw, i.e. base thickness, the wedgeangle be large enough, the wedge height be high enough and the slotwidth in the lateral dimension be small enough, so that enough wateraccumulates in each straight slot to significantly reduce directnon-impact transmission of throw through the straight slots, thisreduction thereby making it possible to eliminate the containment regionand allowing the condensed water to flow directly to the road surface;

the importance or realization that following tires will have spraycontrol equipment, and moreover, the largest amount of the water hasbeen splashed laterally, so that the water returned to the tire tracksfrom the throw does not create a great problem;

the importance or realization that in using wedge arrays with slantedslots, the slots must be slanted enough and made long enough, i.e. thebase made thick enough, to block direct transmission of spray;

the importance or realization that slanted slot arrays can be designedto deflect the condensed water in the direction desired, for example,over an overwheel array to fall inside the tires or with split flow,half inside and half outside the tires, a slight tilt downwardly towardthe center assisting inward flow and a slight tilt downwardly andrearwardly of overwheel spray controllers behind single tires, duals andrear tandems assisting rearward flow of the deflected water;

the importance or realization that a crosswind blows the water from thebottom of a side skirt laterally to fall upon a tire and become sprayagain; and

the importance or realization that the air passing under a vehicle is inpart dragged along with the vehicle and therefore that water made tofall inside the tire tracks into this dragged air between them, does notbreak into as fine a spray as that falling into the high shear airstreamoutside the tire tracks.

SUMMARY OF THE INVENTION

This vehicle tire water spray control system provides better spraycontrol, overcoming many of the deficiencies of prior spray controlsystems, and in doing so uses materials more economically and moreeffectively. The drivers of vehicles following vehicles equipped withthis vehicle tire water spray control system enjoy improved visibilityof the roadway ahead of them, improving their efforts to drive moresafely.

Each embodiment of this spray control system has a receiving side and anopposite side. The receiving side comprises a plurality of symmetric orasymmetric wedges or ribs integrally formed with and extending outwardfrom the planar surface of a base or its equivalent, in some cases thebase being hollowed out beneath the wedges to reduce weight, cost ofmanufacture, and cost of materials. The symmetric wedges used on anunperforated base are at least 9/32 inch high for effective coalescence,but 15/32 inch or less in height for effectiveness in spray control,convenience of shipping, handling and installation, and for economy ofmanufacture. In some embodiments used in positions where the spray isless dense, the wedges abut one another. In others, exposed to moredense spray, they are spaced closely apart, but not more than 37% of thebase width of the wedges, some embodiments having straight or slantedslots between the wedges. Symmetric or asymmetric wedges are used withslanted slots between. On side skirts, exposed only to the low speedmist from high speed throw impacting nearby surfaces, the horizontalwedges and ridges may be spaced farther apart, but the close spacing ismore effective.

In the slotted embodiments a plurality of slots extend through the basebetween the wedges either perpendicularly, requiring larger apex angleson the wedges, other dimensions remaining equal, or thicker bases ornarrower slots to accumulate enough water in the slots to prevent directnon-impacting transmission of throw through the spray controller, or inslanted fashion blocking direct through transmission with the rear wallof the slot. The slanted slots provide channels through the spraycontroller base through which water droplets and condensed water fromthe spray may pass after impacting a wedge or slot surface. In respectto this array, coalescence and deflection of the throw occur throughoutthe entire process.

The various spray controller embodiments are positioned in proximity tothe tires. They include fender flap spray controllers, floor sill spraycontrollers with and without gutters, overwheel, between tractor tandemand general purpose spray controllers with wedges facing the throw, thefloor sill spray controller being designed with a gutter in two designsto guide the coalesced water to fall in the relatively quiescent airtoward the center of the vehicle rather than falling back onto rotatingtires. The preferred overwheel spray controllers require slots allslanted in one direction to direct the water above the spray controllertoward the center of the vehicle, a slight slope downward toward thecenter, and barriers along the front, rear, and outside edges to preventwater from falling back upon the tread where installed ahead of fenderflaps. The overwheel spray controllers may use asymmetric wedges toprovide more efficient, less turbulent, efflux from the slots.

In both positions, when used over dual tires, the overwheel spraycontroller will best have longitudinal strips along its center and alongthe inner and outer edges where little throw impinges, devoid of wedgesand slots to prevent water from falling back upon the tires, the basesloping downward toward an inner barrier wall which has openings at boththe forward and rearward ends, making the device interchangeable fromthe left side to the right side of the vehicle by 180 degree rotation.

An alternate design of the overwheel spray controller provides splitflow, wedges on the left, symmetric or asymmetric, combined with slantedslots directing water on the left side to flow to the left, and that onthe right side to flow to the right. In this case a bare strip at theouter edge, devoid of wedges and slots, tilting downwardly and outwardlyand an outer gutter are introduced. In this case forward and rearwardopenings through both inner and outer barriers drain the gutters. Thisspray controller is mounted substantially horizontally over tandems, butmay have a downwardly, rearwardly tilt behind tandems, duals and singletires.

Side skirt spray controllers having horizontal ridges or wedges aredesigned with greater wedge or ridge separation. They condense thesecondary, slow-moving finer mist that flows laterally from the highspeed impact area above the tires. This condensed water flows down toand along the preferably horizontal or near horizontal upper surfaces ofwedges or ridges to fall the fender flap at rather ends being blown in acrosswind to fall upon the tire tread thereby generating copious spray.Skirts on the side facing into a storm's cross wind bend inward makinggutters of the formerly horizontal wedge surfaces assisting the rearwardflow. An alternate form of side skirt has vertical wedges with slantedslots between and a gutter below. These wedges may also be mounted on anunperforated base. The preferred vertical wedge design has slanted slotsto direct the water and air rearward. It provides more effectivecoalescence by drawing more of the mist through the slots via theBernoulli Effect, rather than having it flow under the side skirt to addto the mist blocking adjacent drivers' vision.

The wedges on embodiments directly intercepting high speed throw may besymmetric, having oppositely sloping faces with the apexes and thewedges being oriented symmetrically toward oncoming throw droplets, inorder that droplets strike the surface at a small angle relative to thesurface, thereby reducing collision energy and consequently sprayformation, or they may have asymmetric wedges to better divert the flowin one direction as with several designs of the overwheel spraycontroller.

Upon striking the sloping surfaces of the wedges, the small spraydroplets in part condense to form larger droplets which then travelalong the sloping faces and into the region between the wedges formingwater which bounces off fender flaps in large droplets during lift ofthe fender flaps or flows downward between the wedges. When slots arepresent, water and droplets flow into them and condense further into astream-like flow to thereafter flow from the slots at the opposite sideof the spray controller and onto the wet road surface. In the embodimentusing straight slots, perpendicular to the base, the slots must benarrow enough and combined with wedges having apex angle, wedge heightand base thickness, i.e. slot depth, large enough, 3/32 to 5/16 inch, toprovide adequate water in the slots to largely prevent non-impact travelof throw through the slots. The slanted slots, when used in the fenderflap spray controller, may be arranged to give flow in one direction, orin a split flow design wherein the slots on the right half of the spraycontroller are slanted to the right side and the slots on the left halfof the spray controller are slanted to the left side, thereby in partdirecting the water away from the tracks of the rotating tires uponbeing discharged from the spray controller. Rather than simplycollecting the spray and allowing it to coalesce in a closed region,these embodiments of spray controllers actually coalesce spray andsuppress spray formation prior to directing the increasingly coalesceddroplets in part away from the tires of moving vehicles so as to reduceimpairment of driver visibility.

The spray controllers are made from an impact resistant, chemicalresistant, abrasion resistant, weathering resistant flexible or rigidmaterial appropriate to the application. Included are materials such ashigh or low density polyethylene, polyurethane, rubber and/or fibre,i.e. uncured residue from making tires or metal, and may be made usinginjection molding, compression molding, or extrusion, the slanted slotsmay be cut in a second process following the initial molding orextrusion.

ON RATIOS

It is interesting that ratios are of importance in the design of wedgearrays on which high speed throw impacts directly. For example:

For a given density of spray in terms of mass per second per square footof area, if the wedge height is increased and its angle remains thesame, the wedge separation, with or without slots, must be increasedproportionately to maintain the same effectiveness by maintaining flowrate per unit area through the slot or downward, toward the road surfacein the case of fender flaps, near the bases of the wedges the same, thesame percent of the wedge projecting from the flowing water.

Where the depth of the slots is of importance for straight slots, aslong as the water per unit area of the slot is maintained the same,varying the slot width in proportion to wedge height as above maintainsthe same blocking power of accumulated water in the slot.

Increasing wedge angles increases the collection area per slot and alsoreduces the average water speed through the slot, thus enhancing theblocking effect, i.e. accumulated water in the slot preventing nonimpacttravel of throw through the slot. It is for this reason that thestraight slot array requires a different wedge angle and therefore adifferent ratio of slot width to wedge base width than do slanted slots.In particular the best results observed for closely spaced apart wedgeson an unperforated base and for slanted slots were obtained at a slotwidth to wedge base width ratio of approximately 25%. The mediocreresults obtained for slanted slots at 37% and bad results at 50% may beexplained by incomplete blockage of throw. In contrast excellent resultswere obtained for straight slots at a ratio of 17% and bad results at23%. Thus an upper limit for the ratio has been selected midway betweenthe good and bad results, namely 37% for closely spaced apart unslottedwedge arrays and for symmetric wedges with slanted slot arrays, by 50%for asymmetric wedge arrays with slanted slots. An upper limit of thisratio has been chosen as 22% for wedge arrays using straight slots. Itis important to note that there are no flanges beside the slots in anyof the arrays. A smooth flow of water and droplets into the slots isconsidered to be essential for best performance.

DESCRIPTION OF DRAWINGS

FIG. 1 is an environmental side view of the tractortrailer vehicle withthe various spray controllers of the vehicle spray control systemmounted at various locations for suppressing, coalescing and directingthe spray such as fender flap spray controllers behind each set oftandems, side skirt spray controllers, floor sill spray controllers,overwheel spray controllers and general purpose spray controllers.Arrows indicate the direction of the trajectory of the spray waterdroplets and the relative angles at which they impact the array ofwedges on the receiving side of the spray controllers.

FIG. 2 is a section of a spray controller showing an array of abuttingwedges.

FIG. 3 is a section of a spray controller showing an array of closelyspaced apart wedges.

FIG. 4 illustrates a spray controller having an array of closely spacedapart wedges separated by straight slots, i.e. slots with center linesperpendicular to the surface of the base.

FIG. 5 shows a spray controller having an array which is inclusive ofslanted slots on side A deflecting spray to the left and on side Bdeflecting spray to the right.

FIG. 6 is a section of a side skirt spray controller using horizontallyaligned wedges, the top surface of which is near horizontal.

FIG. 7 is a section of a side skirt spray controller using horizontalridges.

FIG. 8 illustrates a fender flap spray controller with an embeddedvertical stiff bar abutting, welded to, or otherwise attached to acrosswise stiff bar near its bottom, thereby providing antilift andantitwist restraints.

FIG. 9 displays an assortment of symmetric and asymmetric wedgegeometries.

FIG. 10 shows an assortment of slots having different wall geometries.

FIG. 11 illustrates a laterally curved overwheel spray controller overthe tire of an auto and a fender flap behind.

FIG. 12 is an overwheel spray controller.

FIGS. 13A and 13B display trailer mounted overwheel spray controllers,the right one shown in FIG. 13B being held in position by a clamp andthe left one shown in FIG. 13A being held by a special holder shown inFIG. 15 into which the controller can be simply inserted or removed, andeasily tilted downward to the centerline or to the rear of the vehicle.

FIG. 14 illustrates the clamp to secure the overwheel spray controllerhaving external steel bars, holders 18 and 19 being modified to obtaintilt.

FIG. 15 is an overwheel spray controller holder that can be mounted on atractor or trailer into which the overwheel spray controller is simplyinserted or removed and does not require internal reinforcement of thespray controller.

FIG. 16 displays an automobile with spray controllers.

FIG. 17 shows tractor-mounted spray controllers, overwheel, fender flap,between tractor tandem, and a vertical, general purpose,tractor-mounted, mirror-protecting spray controller.

FIG. 18 shows trailer mounted overwheel spray controllers over tandemaxles without a between tractor tandem spray controller.

FIG. 19A is a floor sill spray controller with slanted slots attached toan I beam type floor sill.

FIG. 19B is a clamp to hold the floor sill spray controller in place.

FIG. 20A is a floor sill spray controller with abutting symmetric wedgesand gutter attached to a channel-type floor sill.

FIG. 21 is a between tractor tandem spray controller (BTTSC) in itsmount as seen from behind.

FIG. 22 is a side view of the BTTSC.

FIG. 23 is a top view of the BTTSC hanger.

FIG. 24 is an illustration of a general purpose wedge array bonded tothe surface ahead of a tractor's front tire, having a gutter below tocarry water toward the center of the vehicle.

FIGS. 25A, B, C, and D are side skirt sections as viewed from the rear.

FIGS. 26A and 26B show comparative spray controller angle coverages.

FIG. 27 illustrates a fender flap at an angle.

FIG. 28 is a fender flap with an external reinforcing horizontalanti-twist bar at its bottom which includes a gutter that empties watertoward the vehicle center.

FIG. 29 is a lightweight flexible hanger for a fender flap.

FIG. 30 is section 30--30 of FIG. 31 showing base 2, asymmetric wedges13A, barriers 23, water velocity vectors VW across the top and down theend and slanted slots 15.

FIG. 31 is an illustration of a plan view of another possible design ofthe overwheel spray controller with asymmetric wedges. VT is the truckvelocity and 150 shows openings in the inner barrier.

FIG. 32 is section 32--32 of FIG. 31 showing barrier 23, base 2, andasymmetric wedges 13A. VTH is the throw velocity.

FIG. 33 is section 33--33 of FIG. 32 showing a best cross section 81 ofthe material between adjacent ends of slots that are end to end.

FIG. 34 is section 34--34 through the rear opening in the inner barrierof FIG. 31 showing the gutter formed at the inner barrier 23.

FIG. 35 is section 35--35 of FIG. 31 showing the central longitudinalband of the base devoid of slots and wedges.

FIG. 36 is section 36--36 of FIG. 31 showing the rear barrier.

FIG. 37 is section 37--37 of FIG. 31 showing the forward barrier.

FIG. 38 is section 38--38 of FIG. 31 showing the forward opening in theinner barrier.

FIG. 39 is section 39--39, a modified section 35--35 of FIG. 31, toillustrate an alternate design for this overwheel spray controller whichalternate design has bidirectional flow, the wedges and slots on theleft deflecting water to the left and those on the right deflectingwater to the right.

FIG. 40 is section 40--40, modified from section 32--32 of FIG. 31, toillustrate the outside gutter of this alternate design for the overwheelspray controller in FIG. 31.

FIG. 41 is section 41--41 of FIG. 31 to illustrate a rear openingthrough the outer barrier for this alternate design of the overwheelspray controller of FIG. 31, this design having both forward andrearward openings in both outer and inner barriers.

FIGS. 42 and 43 illustrate configurations of symmetric and asymmetricwedges contiguous to slots having angles greater than the contiguouswedge slopes.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Introduction

A vehicle spray control system, FIG. 1, apparatus and method areprovided for suppressing, coalescing and directing "throw" thrown fromrotating tires 11 of vehicles 4 via centrifugal forces generated by therotating tires during travel of the vehicles 4 along the wet roadsurfaces. Wet road surfaces pose the hazard to drivers of visionimpaired by spray from other vehicles particularly tandem tractor 3trailer 5 combinations, and trucks as well as their own vehicles. Waterdroplets of the "throw" impact various surfaces on the vehicle,fragmenting into smaller droplets of mist, making it nearly impossibleat times for a driver travelling behind or downwind to see even with thewindshield wipers on. High speed travel of larger tractor trailercombinations, having tandem axles and several sets of dual tires,generate large amounts of spray and mist, especially between the tandemaxles 28 and 29 of the tractor 3. The preferred embodiments of thisinvention are particularly adapted for use with tractor-trailercombinations whereby different embodiments of spray controllers 27 arepositioned in selected locations on the tractor 3 and trailers 5 tocontrol and direct the spray thrown by the tires, thereby suppressingthe formation of mist by requiring high speed droplets to strike wedgesurfaces at small angles. Thereafter, the droplets become coalesced intolarger droplets and ultimately become discharged as larger dropletsand/or flowing water streamlike in appearance while being directeddownwardly, laterally, and/or away from the rotational path of the tiresof the vehicle. Other embodiments or applications of the vehicle spraycontrol system apparatus however, may be adapted for use withautomobiles, with airplanes traveling on a runway or boats traveling onthe water, for example.

Nine Physical Principles Underlie an Effective Vehicle Spray ControlSystem

The effectiveness of the vehicle spray control system is based on theapplication of eight physical principles: first, a water droplet'scollision energy with a surface and, therefore, the amount of spraygenerated by such collision is dependent upon the speed and direction ofmotion of the droplet relative to that surface, whereby the collisionenergy is decreasing continuously from a maximum when the direction ofmotion of the droplet is at normal incidence relative to the surface, toessentially zero when the direction of motion of the droplet isessentially parallel to that surface. Second, water droplets in mist andspray condense to form larger droplets of water more rapidly as theirconcentration increases by compression as it moves toward the bases ofthe wedges, or by glancing incidence on a wet surface. Third, with aconstant rate of impact of throw per unit area of spray controller,water per unit cross-sectional area of collecting slots increases withthe collection-area drained per slot and with the slot depth, i.e. basethickness, thus increasing with wedge angle, with wedge height, withbase thickness and with decreasing slot width, thereby reducingnonimpact transmission of spray through straight slots more effectivelyby the same changes in variables, the effectiveness of spray suppressionper unit area normal to the throw is proportional to the percent ofeffective wedge surface area available for impact by the throw, i.e. thewedge surface area extending beyond any water flowing between thewedges, plus effective in-slot suppression area available for impact bythe throw. Thus, excessive water accumulation which reduceseffectiveness by covering portions of the wedges is reduced by slotswhich transmit water through the base of the spray controller. Fifth,increasing slot cross-section increases the maximum water flow ratethrough the slot and decreases accumulation of water on the impact sideof the spray controller, thereby maintaining suppression better in heavythrow, i.e. for deep water on the roadway. Sixth, for a given wedgeangle and base thickness, the ratio of lateral wedge separation to wedgewidth must remain constant to maintain a given effectiveness of spraycontrol, because the water flow between wedges keeps the percent ofsurface area above the water flow constant and the density of water perunit area in slots constant for a given ratio. Seventh, throw strikingat near normal incidence to a wedge array with slots passes through theslots more efficiently as the flow distance along the wedge surfacedecreases, the effectiveness of a slotted array is increased as the endto end longitudinal separation of slots decreases compared to thelongitudinal length of the slot. This can be referred to as thelongitudinal slot separation to slot length ratio. Ninth, side skirtswith horizontal wedges reduce the amount of water falling directlydownward beside the wheels, that in a storm's side wind blows onto theupwind tires, and also reduces the amount of water caught in the upwindcaused by tire rotation ahead of a fender flap, by carrying asignificant amount of this water to fall behind the fender flap becausethe differential pressure is lower behind the fender flap than ahead ofthe fender flap.

Thus, the optimum combination of wedge height, wedge angle, wedgeseparation, i.e. slot width if slots are used, and base thickness ifslots are used, depends on the water depth on the roadway and thepositioning and function of a given spray controller. For example,abutting wedges would be adequate for floor-sill spray controllers whichreceive less dense throw than do fender flaps or overwheel spraycontrollers. Straight slots are best behind wheels, and slanted slotsessential over the wheel. But, although more expensive to manufacture,slotted versions out perform unslotted designs.

Method of Suppressing, Coalescing and Direction Larger (Water) Dropletsand a Stream-like Flow of Water Through the Spray Controller:Application of the Nine Physical Principles

The first physical principle is evidenced by the fact that the slopingfaces 31 of the wedges 13 and the forward surface 41 and rearwardsurface 42 of the slots are positioned at an angle relative to theoncoming water droplets of the spray such that the droplets of waterstrike the wedge sloping faces and slot surfaces at grazing incidence,generally not more than 20 degrees from surface parallel for symmetricalwedges with unslotted embodiments, not more than 30 degrees forsymmetric wedges with slanted slot embodiments, not more than 45 degreesfor the asymmetric wedge of FIG. 9D with slanted slot embodiments, butover 20 degrees for symmetrical wedges used with straight slots.

The droplets' first impact is of energy proportional to 1/2 m (v sin φ)²where m is the mass and φ is the angle between the velocity and thesurface parallel. Collision energies at angles of 45, 30, 15 and 10degrees are reduced to 0.5, 0.25, 0.067 and 0.030 respectively times thevalue at normal incidence. Thus water droplets break into fewersecondary droplets than they would at normal incidence. Those dropletsof water that do not wet the wedges 13 and flow along their slopingfaces will bounce off the wedge sloping faces at small angles. Glancingimpacts of the spray droplets convert more energy to heat because ofenhanced surface and internal friction rather than to increase surfaceenergy by mist formation. Collisions of the secondary droplets of wateroccur generally at lower speed, many on the opposite wedge face. Uponimpacting the sloping wedge faces in secondary collisions, the secondarydroplets of water will coalesce to form larger droplets and eventuallymost remaining droplets pass into the slots 15 or into the downward flowof water between the wedges 13.

Application of the second physical principle is illustrated with goodexperimental results in relation to abutting wedges and to the closelyspaced apart wedges with nominally 1/16 inch separation at the point ofjunction of 7/16 inch high, 35 degree symmetric wedges 13 with the base2, unslotted; or having 45 degree 7/16 inch high symmetric wedges withlongitudinally aligned straight slots through a 1/4 inch thick base, andto the configuration with 7/16 inch high 35 degree wedges with slantedslots through the base at the wedge half angle of 17.5 degrees. As thewater droplets of spray approach the receiving surface 47A, they passbetween the apexes of the wedges; their concentration increases as theyapproach the base through the increasingly constricted area and themist-like droplets thereby increase their rate of coalescence. Glancingimpact of the water droplets on the wedge sloping faces 31, and onrearward surfaces 42 of the slots in the slanted slot configuration,also enhances further coalescence of the water droplets from the sprayto eventually form larger droplets and a flow of water which isstream-like in appearance.

Water droplets and residual spray, if impacting nearly perpendicularlyto the base, also move through the thick base through slots 15 or 15A athigh speed, except slowed more for larger wedge angles. Symmetric wedgesof 7/16 inch height and 45 degree apex angle experimentally allowed 1/16inch wide by 1/4 inch deep straight slots, i.e. a slot width to wedgewidth ratio of 17%, to be extremely effective by virtue of physicalprinciple number 3 collecting enough slow velocity water to effectivelyprevent non-impact transmission of high speed throw through the straightslots 15A. Whereas symmetric wedges with 35 degree apex angles, i.e. aslot width to wedge width ratio of 23%, were found to be ineffective for1/16 inch wide straight slots using 7/16 inch high wedges. Physicalprinciples 4 and 5 were experimentally well satisfied using the formerparameters for straight slots and fairly heavy water throw. Thus, forstraight slots an upper limit for this ratio is selected as 22%, lessthan the ratio 23% for which experimental results were poor. Thusphysical principle 6 is evidenced as preferably a 17% ratio for straightslots. For higher wedges or larger angles thinner bases are effective,whereas lower wedges or narrower angles require thicker bases. Forstraight slots a range of base thicknesses is from 3/32 to 5/16 inch, ofwedge heights 7/32 to 15/32 inch, wedge angles 40 degrees minimum, and awedge spacing no more than 22% of wedge base width.

For unslotted and slanted slot arrays mediocre results wereexperimentally obtained using 3/32 inch separation and poor resultsusing 1/8 inch separation between symmetric wedges for both unslottedand slanted slot bases at 35 degree apex angle, 7/16 inch high wedgesand 1/4 inch base thickness, the poor results for slanted slots beingcaused at least in part by incomplete blockage of directly transmittedspray, to be compared to excellent results for the same configurationsand parameters with 1/16 inch wedge separation between the symmetricalwedges at the base; thus for closely spaced apart unslotted arrays anupper limit for the lateral wedge spacing to wedge base width ratio isselected as 37%, midway between the excellent results observed at 25%and the poor results observed at 50%. Thus physical principle number 6is evidenced as 25% between symmetrical wedges and closely spaced apartunslotted arrays. Thus wedge heights are from 9/32 to 15/32 inch, wedgeangles 30 to 40 degrees and separation ratios 37% or less. However, anupper range of 50% is chosen for symmetrical and asymmetrical wedgearrays with slanted slots providing complete blockage of directlytransmitted spray. For asymmetrical wedges 1/4 inch high, 35 degrees,with 1/8 inch thick base and 1/16 inch wide slots of length 1 inch andend-to-end spacing 1/8 inch good experimental results have been attainedat this slot width to wedge width ratio of 36%.

Principle number 7 is evidenced by maintaining the throw impactdirection as nearly normal to the slotted arrays as possible and thewedge height low, thereby preventing fenders with high wedges curvedalong the longitudinal direction of the wedges from being effective.Thus fender flaps, overwheel spray controllers, floor sill spraycontrollers, and between tractor tandem spray controllers are evidencedto control direct throw and have parameters as shown above.

Principle number 8 is evidenced by keeping the longitudinal, end to end,slot separation as short as possible consistent with adequate lateralstrength. Experimentally good results were obtained at 33% or 1/4 inchseparation and 3/4 inch slot length. Better ratios less than 33% will bepossible using metal, plastics such as high or low density polyethylene,urethane or a fibre plus new rubber or new rubber only with lateralstrands of high strength fibers such as those sold under the trade namesof Aramid or Kevlar, indicated as dashed lines 18 between the slots inFIGS. 4 and 5. This ratio maximum is 35% and the minimum slot length 1/2inch. Physical principle 9 is evidenced by results using 35 degreesymmetric wedges horizontally aligned on a side skirt and extending tothe fender flap behind the rear tandem tire, while running in the rainat 55 m.p.h. A film indicates that the water is blow rearwardly as itflows down across the wedges on the inner side of the skirt as it isseen falling largely near the fender flap. Horizontal upper surfaceswill make this flow more efficient with a significant amount of thiswater falling behind the fender flap.

The Vehicle Spray Control System Apparatus Centers on the Use of SprayControllers

As shown in FIGS. 2-7 of the drawings, the spray controllers 27 of thevehicle spray control system apparatus, have a receiving side 47A and anopposite side 47, and comprise arrays of parallel, closely spaced apartwedges 13, or 13A shown in FIG. 32, aligned with the rotational planesof the tires, or spaced apart wedges 13A or ridges 13B with nearhorizontal upper surfaces 31A and 31B which are integrally formed with abase 2 which extends from the base of the wedges to the opposite side.The base for surfaces receiving direct impact of high speed throw isillustrated as having a planar surface although it may be curved forapplications shown in FIGS. 11, 16 and 24. The dashed lines of FIGS. 2,3, 4, 5 and 9 indicate a hollowing of the base below the wedges for thealternate embodiments in which case the "opposite side" is defined as ifthere were no hollowing. The hollowing increases speed of manufactureand reduces materials required, thereby reducing cost. Also, the lighterweight is preferred by truck fleet managers.

The symmetrical wedges 13, each shown having opposite sloping faces 31,which, in arrays receiving high speed throw, directly converge at theiroutermost point at an apex wherein the wedges 13 are arranged on thebase 2 to point symmetrically toward the oncoming spray as it is thrownfrom the tires 11 during travel of the vehicle 4 along the wet roadsurface. The bisectors of the sloping faces 31 of the wedges 13 arepositioned in parallel alignment with the plane of rotation of thewheels and tires of the vehicle. The side skirt spray controllers 6,however, have wedges 13A or ridges 13B in which the upper faces 31A and31B are near horizontal and positioned as shown in FIG. 25B and 25Cperpendicularly to the plane of rotation of the tires facing the mistformed over the tires. The overwheel spray controller of FIGS. 30-38illustrates the use of asymmetric wedges 13A of FIG. 9D with slantedslots as in FIG. 30 to direct the efflux from the slots toward thevehicle center line. FIG. 33 shows a cross section 81 of the materialbetween the ends of aligned slots, rounded to improve flow of water intothe slots. FIGS. 39 to 41 together with FIG. 31 illustrate an alternateoverwheel configuration having bidirectional flow and both external andinternal gutters.

The most fundamental embodiment of the spray control surface 301 isshown in FIG. 2 where adjacent wedges 13 are longitudinally aligned inthe spray suppressing and coalescing surface array and in contact at thereceiving side of the base.

The symmetrical wedges of FIGS. 2 and 3 must be high enough, in therange of 9/32 to 15/32 of an inch, from their base to apex, to allow theimpact of water, droplets, and spray on their surfaces, while water runsdownwardly near their bases to a gutter or to the road surface, or largecoalesced drops fall from the surface, if inclined during lift, to fallto the road. The maximum height is selected to avoid excess cost ofmanufacture, for convenience of installation, and to maintain someflexibility for modest lift. The wedge apex angle must be large enough,at least 30 degrees, to allow space for the water to flow, yet smallenough, 40 degrees or less, to significantly reduce the impact energy ofcollision with the surface.

In the second most fundamental embodiment of the spray control surfacewith an unperforated base, 302, FIG. 3, the longitudinally alignedwedges are shown spaced closely apart, preferably 25% but no more than37% of the width of the wedge base, in the array to allow water to flowmore freely along the space between the wedges under heavy waterconditions. Assuming constant throw rate the effectiveness ofcoalescence and suppression gradually decreases as the separation ofwedges at their contact with the impact side of the base increasesbecause the percent of the lateral area effective in suppression andcoalescence decreases. In contrast, as the throw rate increases fromwetter surfaces, however, the water with wedges separated can flow ingreater volume along the receiving side of the base, leaving a largerportion of the wedge beyond the water. To assure adequate control ofthrow by fender flaps, angles, heights and separation of wedges arerestricted as previously discussed.

In the most fundamental embodiment of the spray control surface 303having perforations through the base between the wedges, as shown inFIG. 4 and best used for fender flaps, elongated slots 15A arelongitudinally aligned and spaced apart between the wedges 13 to formapertures through which water and air may pass during travel of thevehicle. Each slot extends through the base, as shown in FIG. 4, atright angles to the surface of the base and extends from the foot of onewedge to the foot of the adjacent wedge, the foot being that portion ofthe wedge which lies in the surface of contact between the wedge and theimpact surface of the base, or the plane of transitions from wedges toslots. In this embodiment a slight divergence of the sides of the slotfrom the wedge base plane to the opposite side will maintaineffectiveness, but reduce the problem of material thrown up from theroadway blocking the flow.

In the most effective but most difficult to manufacture embodiments ofthe spray controllers 27 receiving direct impact of high speed throw,slanted slots extend through the base 2, being longitudinally alignedand spaced apart between the wedges 13 to form apertures through whichwater and air may pass during travel of the vehicle. This slanted slotarray is especially valuable over the wheels. As shown in FIG. 5 eachslot has a forward surface 41 and rearward surface 42 with the rearwardsurface being a continuation of a sloping face of the adjacent wedge 13.As shown in FIG. 5, the slots 15 extend through the base 2 slanted at anangle relative to the planar surface 43 of the base 2 to prevent thespray from passing directly through the slot 15 without impact, wherebyit provides the impediment to the motion of the water droplets, therebyassisting in the coalescence of the water droplets of the spray anddirecting the larger water droplets and coalesced stream-like flow ofwater in the direction desired.

The primary embodiments of the fender flap spray controllers are eitherunslotted or have straight slots 15A between the wedges or have aplurality of wedges 13 or 13A and slots 15 utilizing a "split flow"design as shown in FIG. 5 whereby the slots 15 on the left half 35 ofthe spray controller are angled to the left thereby directing largedroplets and stream-like water from the left of the opposite side 47 ofthe spray controller to the left and the slots 15 on the right half 34of the spray controller 27 are angled to the right so as to direct thelarger droplets and flow of stream-like water from the right of theopposite side 47 of the spray controller to the right.

The primary embodiment of the overwheel spray controller has a centerflow design. In this embodiment the slots are all slanted in onedirection. These slots direct the water flow, from the coalesced andsuppressed upwardly moving throw of spray and water, toward the centerof the vehicle. Thereafter the collected water falls beyond the tires,in relatively quiescent air.

In the event that manufacturing costs are prohibitively expensive forslanted slots, the straight slot array of wedges may be used over thewheel, the array being tilted downward toward the vehicle center andbarriers may be used to prevent forward, rearward and outward flow offthe controller. More water will, however, with this design, fall backupon the wheel than when slanted slots direct the water over thecontroller toward the vehicle center.

Economy of manufacture may be achieved for these and other controllersand performance enhanced by eliminating slots and wedges in longitudinalstrips along their centers, along their inside edges and along theiroutside edges over, ahead of and behind duals for which the controllersare generally about 24 inches wide, because little spray normallyimpacts these positions and for overwheel controllers some water wouldfall through such slots and fall back upon the tire.

The inner portion of the base plane of overwheel spray controllers mayhave no wedges or slots, but slope downward to an inner barrier to forma shallow gutter, FIG. 34, the inner edge having a barrier 23 that hasopenings 150 fore and aft to allow the water to flow in a stream towardthe road surface.

On Wedges and Slots

Asymmetric wedges may be used to allow the plane of symmetry of thewedges to lie in the plane of the wheel rotation, where the base iscurved laterally as in FIG. 11. Curved "wedge" surfaces such as theconfigurations B1 or C2 in FIG. 9 may be used to increase impactstrength. Configurations D and E of FIG. 9 combined with slanted slotsprovide more efficient deflection of the efflux from the slots in adesired direction with less turbulence allowing greater slot angles upto 45 degrees and smaller base thicknesses to 3/32 inch. The curvedconfiguration E may be used to improve the flow of water into the slot.The configuration F may be used with unslotted arrays to allow morewater to flow between the wedges at constant separation whilemaintaining effective spray control.

Curved slots, as shown in FIG. 10, configuration C, can be used tobetter direct water flow in a desired direction. Divergent slot widths,as in configurations E and H, can be used to reduce slot blockage,caused by debris. The divergence is indicated by dashed line 16 in FIG.5.

Slot angles greater than wedge angles, as shown in FIGS. 42 forsymmetric and 43 for asymmetric wedges allow the efflux from the slotsto be more nearly parallel to the surface. Manufacturing is difficultfor such a design.

The Spray Controllers of the Vehicle Spray Control System ApparatusComprise Several Embodiments. Adapted for Use, for Example, onTractor-Trailer Combinations

FIG. 1 shows a vehicle 4, such as a tractor 3, trailer 5 combinationequipped with the various preferred embodiments of the spray controllersof the vehicle spray control system apparatus, including: fender flapspray controllers 1, 1A located behind the steering axle of the tractor3, 1B behind the rear tire of the tractor tandems 28 and 29, and 1Cbehind the rear tire of the trailer tandems; a side skirt spraycontroller 6; an overwheel spray controller 7; a floor sill spraycontroller 9; general purpose spray controllers 10 shown ahead of thesteering tire, on the fuel tank ends and ahead of the forward tractortandem to protect the mirror from throw; and a between tractor tandemspray controller 12.

The Fender Flap Spray Controllers of the Vehicle Spray Control SystemApparatus

The fender flap spray controllers, using wedge arrays shown in FIGS. 2,3, 4, 5, and 35 are suspended vertically from the vehicle behind therotational path of the tires of both the tractor 3 and the trailer 5. Apreferred orientation as shown in FIG. 27 is at an angle. The wedges 13or 13A in all fender flap embodiments are positioned in parallelalignment with the planes of rotation of the tires.

Fender Flaps With Closely Spaced Apart Wedge Arrays

FIGS. 2 and 3 illustrate the unperforated, i.e. unslotted, version ofthe fender flap spray controller 1 wherein the wedges are shown abuttingin FIG. 2 and closely spaced apart in FIG. 3, the latter allowingheavier flow of water between the wedges, but the former providing, inless dense spray, the greater percent surface area for spray suppressionand coalescence. In realistic on-road conditions with normal lift of thespray controller or slanted installation of a more rigid fender flap inFIG. 27, the abutting wedges provide effective suppression andcoalescence because the large coalesced drops tend to bounce out andfall to the roadway rather than flow nicely between the wedges to thebottom of the controller and thence to the road surface. The lowerwedges are more economical to make, to ship, and to install. Theeffective area is enhanced by increasing wedge height where water flowsbetween the wedges. Wedge height is from 9/32 to 15/32 inch Wedgeseparation is less than 37% of wedge width.

The design is self cleaning. Under heavy water conditions, the closelyspaced apart array is preferred. In this case the ratio of wedgeseparation to wedge width of 25% provided excellent experimentalresults. Where hollow wedges are used, illustrated by the dashed lines 8in FIGS. 2 to 4 and by the wedges, second from left in FIGS. 5A and 5Band in FIG. 9, weight is reduced as is also the cost of material andcost of production because the molding time is reduced although the moldcost is increased. Also the mold cost is less for lower wedges.

Fender Flaps With Straight Slots Between Closely Spaced Apart Wedges

FIG. 4 illustrates the closely spaced apart wedge array having slotsperpendicular to the base. Although more effective in controlling spray,it is also more expensive to manufacture. Experimentally it was provento provide excellent spray control with wedge apex angles of 45 degrees,wedge height of 7/16 inch, slot width to wedge base ratio of 17% using1/16 inch wide slots, wedge bases 0.36 inch wide, and a base thicknessof 1/4 inch. Variation of wedge height or angle requires variation ofslot width and/or base thickness. Thus, the range of slot widths is from1/32 inch to 3/32 inch and the range of base thickness is from 3/32 inchto 5/16 inch. Other parameters identical, straight slots gave poorresults using 35 degree wedges or a 23% ratio. Thus an upper limit of22% for this ratio of slot width to wedge base width is selected. Therange of wedge heights is from 7/32 to 15/32 inch.

Effectiveness improves with slot length for a given end-to-end slotseparation. The ratio of end-to-end slot separation divided by slotlength attainable is dependent on the strength and rigidity of thematerial of construction. Experimentally, slot lengths used through 1/4inch thick neoprene rubber have been 3/4 inch with 1/4 inch end-to-endseparation; and, using 90 durometer rubber 1/8 inch thick, slot lengthsof 1 inch and 1/8 inch separation were used, but only with slantedslots. Metals and plastics, including high and low density polyethylene,allow smaller slot separations. Thus, the ratio of end-to-end separationof slots divided by slot length is less than 0.35, and the minimum slotlength 1/2 inch.

Use of this configuration of straight slots and wedges for fender flapsallows water to be deposited back into the tire tracks, but the amountis negligible compared to that originally on the roadway and followingtires may also have spray control.

The embodiment using the wedge array of FIG. 4 is easier to pull from amold than the split flow design of FIG. 5 but not if a slight taper isintroduced to make the downspray end slightly wider than the wedge end,which would serve to reduce blockage by debris.

Fender Flaps With Slanted Slots Between Closely Spaced Apart Wedges

FIGS. 5A and 5B illustrate the preferred, but most expensive embodiment,the split flow design of fender flap spray controllers 1 wherein theslots 15 slant to the left side on the left half 35 of the spraycontroller 306 while slots 15 on the right half 34 of the spraycontroller 306 are slanted to the right side to permit the now coalescedstreamlike flow of water to be discharged from the slots 15 on thedownspray side 47 of the spray controller 1 away from the tracks of thetires and to fall in part outside the path of the tires of the vehicle.To facilitate self cleaning, the rearward 42 and forward 41 surfaces ofthe slanted slots 15 may be slightly divergent to each other with therearward surface of the slot being a continuation of the wedge slopingface half angle.

Slot widths range from 3/64 to 1/8 inch at the bases of the symmetricwedges or 1/32 to 1/8 inch between asymmetric wedges and they arecontiguous thereto. The base thicknesses range from 3/32 inch to 5/16inch, or, if hollow wedges are used, the slots have an equivalent depth.Wedges range from 3/16 to 5/8 inch high. Symmetric wedge angles are 30to 60 degrees. Asymmetric wedge angles are a maximum of 45 degrees. Slotangles continue the wedge angle through the base, the rear wall of theslot preventing non-impact passage of throw through the base.

Excellent experimental results were obtained from the symmetric wedgeembodiments of FIGS. 5A and 5B for a configuration with a base thickness1/4 inch, wedge height 7/16 inch, wedge lateral separation and slotwidth 1/16 inch, slot longitudinal separation 1/4 inch, and length 3/4inch, and wedge apex angle 35 degrees.

Good results were also obtained using 1 inch long slots, 1/8 inchend-to-end separation, 90 durometer 1/8 inch thick red rubber, 1/4 inchhigh asymmetric wedges having one side perpendicular to the base and theother side slanted at 35 degrees, the same slope as the 1/16 inch wideslots between.

Thus, lateral wedge separation to wedge width ratios of 25% and 36% andlongitudinal slot separation to length ratios of 33% and 12.5% were usedexperimentally. Improved longitudinal slot separation to slot lengthratio may be obtained for weaker materials by using crosswise fibersbetween the slot ends. Materials such as those with the trade namesAramid and Kevlar may be used. Greater lateral strength can also beobtained by molding from plastics such as low or high densitypolyethylene, urethane or metal. The ratio is less than 35% and theminimum length 1/2 inch.

Use of Fender Flaps With Overwheel Spray Controllers

It is deduced that when used with overwheel spray controllers 7 mountedabove and just forward of the fender flap spray controllers that asmooth top portion 43T, i.e. with no wedges, of the fender flap sprayreceiving surface 47A in FIG. 28 will provide better spray control bydiverting a portion of the upward moving throw to the overwheel spraycontroller.

Anti-sail and Anti-twist for Fender Flaps

Each fender flap embodiment may utilize anti-lift and anti-twist devicesavailable in the market consisting of a heavy steel wire bent to enclosethe lower part.

FIG. 8 is an anti-twist, anti-lift configuration. A pair of stiffanti-twist, anti-sail members 14 are embedded in or securely attached tothe fender flap spray controller. The members are positioned at rightangles to one another, one 14V extending vertically from the hanger areadown the center where wedges are less important, abutting or attachedsecurely to a crosswise member 14H or 14HG at or near the bottom whichin turn is securely attached to or embedded in the material of thefender flap. This configuration maintains the orientation of the spraycontroller near to perpendicular to the planes of rotation of the tiresand keeps it from lifting excessively out of position by wind forcesduring travel of the vehicle.

Such anti-sail and anti-twist members 14V and 14HA or an external devicewith or without gutter are preferably used in all embodiments of thefender flap spray controller 1.

A curved lower edge on the receiving side of the spray controller willreduce shearing into spray by forces of air flow. An external horizontalreinforcement at the bottom in FIG. 28 includes a gutter 14HG in itsforward edge that drains toward the center of the vehicle.

Fender Flap Used on Automobile

FIGS. 11 and 16 illustrate any of the above described fender flap spraycontrollers hung behind automobile tires.

The Overwheel Spray Controller of the Vehicle Spray Control ApparatusUsing Symmetric Wedges for Impact Strength

FIGS. 12 and 30 to 41 show overwheel spray controllers 7 with symmetricand asymmetric wedges respectively which are most effectively positioneddirectly above the upward moving portion of the rotating tires 11 of thevehicle 4 where the angle of impact of thrown droplets is nearly normalto the planar surface 30 of the base 2 of the overwheel spray controller7. Inner and outer longitudinal strips devoid of wedges and slots mayrun along the inner and outer edges, tilting downward to thecorresponding barrier if desired to form gutters, where little upwardmoving throw impinges. A similar central strip is introduced over dualsto prevent water from flowing downward through slots to fall upon thetire tread creating more mist. The region most directly above the top ofthe tire is usually avoided because of occasional tire impact againstthe bottom of the trailer. To avoid tire impact on the wedge array, itmust be mounted on an axle fitting or, if mounted on the tractor frameor trailer, its forward edge must be a distance behind the top center ofthe tire dependent on wedge height and tire diameter. Lower wedges allowcloser placement and thereby greater spray control coverage. Wedgeheights range from 3/16 to 5/8 inch.

One preferred embodiment of the overwheel spray controller 7 utilizesthe symmetric wedge 13 and slanted slot 15 arrangement of the fenderflap spray controllers 1 whereby the bisectors of the sloping faces 31of the wedges 13 are parallel to the plane of rotation of the tires 11.The overwheel spray controller 7, shown in FIGS. 12 and 13B is mountedto the vehicle 4 with two longitudinal bars 17B positioned at each sideof the spray controller 7 which are welded to or are integral with apair of embedded crosswise bars or rods 17A near opposite ends of theoverwheel spray controller as shown in FIG. 12. The externallongitudinal bars 17B slide into central fittings 18 which are locatedtoward the center of the trailer 5 and lock into quickdisconnectfittings 19 with eccentric clamps 20, attached to the floor sills 21with wing screws 22 or bolts at the sides of the trailer 5, as shown inFIGS. 13 and 14.

The supports of the overwheel spray controller 7, in reference to thefittings 18 and 19, are designed to tilt the spray controller slightlydownward, rotation 156, toward the longitudinal centerline of thevehicle, if desired, especially when it is used between tandems. Inaddition, the supports can tilt the overwheel spray controller 7downwardly and rearwardly, rotation 155, when it is used behind thecenter of the rear tires of tandems, or behind the centers of singleaxles.

A central longitudinal bar 17C provides stability and strength for theoverwheel spray controller 7, such as supporting ice collecting on thecontroller 7 in winter and assists the lateral runoff of the stream-likeflow of water after being discharged from the slots at the opposite sideof the base 2. FIGS. 13A and 13B illustrate the path of travel of waterdroplets into and over the overwheel spray controllers 7 on both theright and left sides of the vehicle respectively. The left holder 19A isthat shown in FIG. 15 which is designed to be mounted on tractor ortrailer, the controller with or without internal reinforcement beingsimply inserted or removed. Ribs 23, also called barriers, along the topover the outer edge and over the front and rear ends, may be molded withor attached to the top of the overwheel spray controller 7, as shown inFIG. 12, to guide the stream-like flow of water laterally, upon flowingfrom the slots, toward the vehicle's center to fall in the relativelyquiescent air inside the tracks of the tires 11 of the vehicle. Rear andinner barriers are essential over tandems and can be used over singleaxles, the inner barrier having narrow openings fore and aft for waterto flow downward toward the road surface. The ribs 23 are also used toprovide separation from a flat surface above or a bonding surface forattachment to flat or curved surfaces of a vehicle when used as ageneral purpose spray controller.

The overwheel spray controller 7 seems more effective than and mayeliminate the need for side skirts 27 in that it suppresses the waterthrow directly, rather than simply coalescing secondary mist, byintercepting a large percentage of throw before it becomes mist. Theside skirt only coalesces the mist moving outward after it is formedfrom high velocity throw impacting over the tire. The mist moving towardthe centerline of the trailer does not normally see a side skirt.

The Overwheel Spray Controller Using Asymmetric Wedges

This example of an overwheel spray controller in FIGS. 30 to 38 uses theasymmetric wedges of FIG. 9D to direct the flow of water toward thecenterline of the vehicle. It is best made of high density polyethyleneand best supported by the holder of FIG. 15. Molded barriers are shownabove the four edges to guide the water flow. An inner gutter is shownand the openings at either end of the inner barrier allow the water toflow in a stream toward the surface. The spray controller isinterchangeable from one side of the vehicle to the other by a 180degree rotation as is the overwheel controller of FIG. 12, the forwardopening becoming the rearward. A central lateral barrier 23A shown hereand in FIG. 12 extends from the outer barrier to the outside of thegutter to add lateral strength to the array if needed. Larger arrays mayrequire additional lateral strengthening barriers.

Elongated overwheel spray controllers with several strengtheningbarriers may be bonded to the flat surface at the front of a trailerabove the tractor tandems to allow for positioning fore and aft by anadjustable fifth wheel, the connecting plate between tractor andtrailer, or for moveable axles at the rear of a trailer.

Either the symmetric or asymmetric wedge designs of overwheel spraycontrollers may use the "split flow" concept, half of the throw beingdirected to the left from the left half of the spray controller, and theother half to the right. In the split flow design, the overwheel spraycontroller must be horizontally oriented laterally and have gutters withopenings fore and aft on both sides. It may be tilted downward aft, wheninstalled behind rear tandems, duals or single wheels. Its value overtandems is questionable. FIGS. 39 to 41 illustrate the modificationsrequired to change this overwheel spray controller to split flow, byintroducing an outer gutter in FIG. 40, openings in the same by FIG. 41,and bidirectional wedges and slots in FIG. 39. Rotation 152 about axis151 in FIG. 31 tilts this spray controller down aft and rotation 153about axis 154 tilts this spray controller downward toward the center ofthe vehicle.

Overwheel Spray Controller Mount

The overwheel spray controller mount 63 illustrated in FIG. 15 is shownwith vertical rods 50A to mount on the tractor frame. To convert to atrailer mount, the vertical rods are bent horizontally instead, asindicated with dashed lines 50B, and the outer portion of the mount andthe inner horizontal extensions are attached to the floor sills withbrackets. The holder, made of heavy rod, 1/4 inch to 3/8 inch diameter,has four segments 52 which support the controller from below and may beused to tilt the controller slightly downward toward the center and/orthe rear of the vehicle. The segments 53 at either end of the controllerand 54 at the side of the controller toward the center of the vehicleare bent to hold the controller securely in place during travel. Bentsection 55 is vertical and holds the controller in position after it isslipped in place under bends 53 and bend 54.

The tractor mounted overwheel spray controllers 7, or 7A, without theembedded steel, also serve to reduce spray when the tractor is runningwithout a trailer. They can be supplemented with floor sill likeframe-mounted vertical spray controllers 10 having abutting verticalwedges with vertices facing aft and a gutter below to carry thecondensed throw inward to fall inside the tires. It is so mounted thatit intercepts forward moving throw from the tires that would otherwisestrike the driver's mirrors. Further discussion under "Floor Sill SprayController" follows.

The Overwheel Spray Controller Used Above Tandem Axles

It is reasoned, but not yet demonstrated experimentally, that the abovespray controllers will be effective when used over the region betweentandem axles without the need for a Between Tractor Tandem SprayController or side skirts. This is evidenced because the throw from thetractor lead tandem tires is exceptionally heavy and the droplets moremassive than the droplets in the exceptionally fine mist formed by thetire-to-tire throw which impacts the tandem tire opposite at speeds of100 mph and more. Thus the heavier more massive throw will tend to carrymuch of the fine mist upward with it to be suppressed, coalesced anddiverted by the overwheel spray controller to fall inside the tires ontoor near the tractor frame and thence to fall to the roadway throughrelatively quiescent air, dragged with the tractor. In this applicationbarriers are best used on all four sides with openings fore and aft inthe inner barrier to drain the gutter formed by the downward tilt of thebase to the plane of vertices at the inner barrier.

The Floor Sill Spray Controller of the Vehicle Spray Control System

FIG. 19 shows floor sill spray controller 9, using symmetric orasymmetric wedges and slots all angled to direct spray toward thevehicle center, and having a barrier to prevent water flow toward theoutside. It is attached to an I beam type floor sill 21 with a mountingclip 26. Upon being coalesced and directed through the slanted slots 15,the stream-like flow of water flows out from the slots on the oppositeside of the base 2 and then is channeled behind the floor sill spraycontroller 9. Attachment of this floor sill spray controller 9 to achannel type floor sill would be similar. Three spring clips 26 hold thefloor sill spray controller 9 in place. Screws, bonding cement orbrackets are used as needed for non I-beam floor sills. Rubber ribs 23are shown molded between the slots on the downspray side at the top andbottom of the floor sill spray controller 9 to assure adequate spacebehind the controller 9 for lateral run-off of a stream-like flow ofwater from the opposite side 47 of the base 2 along the floor sill 21 tofall inside the tracks of the tires of the vehicles onto the roadsurface through the relatively quiescent air near the center of thevehicle.

The configuration has wedge heights from 3/16 to 5/8 inch, slot widthfrom 1/32 to 1/8 inch, and symmetric wedge apex angles from 30 to 60degrees or asymmetric wedge angles with one side vertical and the otherside sloped at angles up to 45 degrees.

The Floor Sill Spray Controller With Dam, Barrier or Gutter

FIG. 20 presents an unslotted vertical array of abutting wedges 301 witha gutter 205 having a lateral wedgelike surface 203 below and rearwardto deflect throw to the wedge array above and having an outside barrier203A to direct water flow toward the vehicle centerline where it fallsin the relatively quiescent air inside the inner tire. The gutter 203 ispreferably molded as an integral part of the floor sill spray controller9A, but may be separately made of the same or different material andattached. Wedge height, symmetric or asymmetric, is as small as possibleyet large enough to provide good spray control. A 7/16 inch wedge heightgave good experimental results. A range from 9/32 inch to 15/32 inchwill provide good spray control and yet avoid excessive height foreffectiveness, lower cost and ease of installation. This design may beattached by bonding, by screws or by a bracket attached to the floorsill 21A into which it may be simply inserted and secured. With gutteran integral part of the controller, it may be attached to any type offloor sill, I beam, U beam or one with square cross section and noopening to the rear.

The Between Tractor-Tandem Spray Controller of the Vehicle Spray ControlSystem Apparatus

The between tractor-tandem spray controller 12 suppresses and coalescesroad surface spray thrown from the tires between tractor-tandem dualaxles 28 and 29. The tires 11 of the tractor-tandem duals partiallyclear a path through the road surface water for the trailer duals tofollow. The water droplets of the spray thrown by the tires of the fronttandem axle 28 strike the tread of the oncoming tires of the rear tandemaxle 29 at speeds up to twice the vehicle velocity, often reaching 110to 130 miles per hour, generating large amounts of very fine spray.

FIG. 17 shows the tractor-tandem bobtailing. Tractortandem axles arespaced farther apart than trailer-tandem axles and thus permit betweentractor-tandem spray controllers 12 to be mounted more readily betweenthem. FIG. 17 shows the between tractor-tandem spray controller 12 inposition between the tandem axles.

In the lower portion of the spray controller the unperforated closelyspaced apart wedges 13 face forward thereby controlling spray thrownrearwardly from the front tandem 28.

The upper portion of the between tractor-tandem spray controller 12 alsohas an array of unslotted closely spaced apart or abutting wedges 13extending rearwardly from the base 2, to control spray thrown forward bythe tires of the rear tandem 29 near the top of the rotational path asshown in FIG. 17. It is possible to use abutting wedges in this upperportion of the spray controller 12 because less spray is generated atthis particular location, the tire having spun off throw for the prior180 degrees of rotation.

The central portion of the between tractor-tandem spray controller 12utilizes a base having no wedges 13. This helps to decrease damage tothe spray controller 12, such as from broken chains. The upper front andlower rear surfaces have no wedges.

Tread throw droplets impacting above the forward wedge portion onsurface 43T of the between tractor-tandem spray controller 12 aredeflected upward by the smooth upper surface of this spray controllerand thereafter in part strike the lower surface of the trailer 5 abovethe tires 11. Use of the overwheel spray controllers 9 in combinationwith the between tractor-tandem spray controllers 12 has been shownexperimentally to be very effective in reducing the large amount of mistgenerated by the throw between the tandem axles. Wedges on the forwardupper surface of this spray controller are avoided because they wouldprevent water striking the upper portion from being deflected to theoverwheel controller. Side skirts used in addition with these otherspray controllers 9 and 12 will reduce the mist even more.

The between tractor-tandem spray controllers 12 must be rigidly securedwithin the narrow space between the tires 11 of the tandem axles. Foreand aft motion cannot be totally eliminated. Wedge height must berestricted because of restricted clearance. Shown in FIG. 21, supportframe 37, comprising vertical members 32 and 33 and horizontal members36 and 38, is secured to the tractor frame 45. Attachment members 40 and44 are used to secure the support frame 37 to the tractor frame 45.Vertical rods 46 and 48 are embedded in the between tractor-tandem spraycontrollers 12 and are welded or rigidly attached to supportingcylinders 54 and 56. The supporting cylinders are in turn secured in ahorizontal position on support arms 50 and 52 by split spring stops 58and 60 and by fixed stops 62 and 64. The supporting cylinders 54 and 56are held rigidly in place by the vertical rods 46 and 48 and areenclosed by a rubber sheath 66. The support is readily lifted from thesupporting fixture on the tractor frame. The between tractor tandemspray controller can also use the split flow symmetric or asymmetricwedge arrays with slanted slots previously described at the top andbottom in the manner just described for the unslotted arrays.

General Purpose Spray Controllers of the Vehicle Spray Control SystemApparatus

FIGS. 2, 3, 5, and the slotted portion of FIG. 30, shown in more detailin FIGS. 34 and 39, also illustrate the wedge arrays of general purposespray controllers 10 such as are bonded to the ends of the fuel tankshown in FIG. 1 and is shown, with gutter, positioned forward of thesteering axle tire shown in FIGS. 1 and 24. The general purpose spraycontroller is an embodiment of wedges, symmetric or asymmetric, with orwithout slanted slots, and with a thinner base frequently havingflexibility to bond to a curved surface but also rigidly constructedwhen used as a shield 10 as in FIG. 17. 7/16 inch high wedges made ofneoprene on a neoprene base, 1/8 inch thick, did extremely wellexperimentally on the ends of a fuel tank. As wedges increase in height,flexibility is lost. Thus a range of heights from 9/32 to 15/32 inch isrecommended for unslotted controllers and from 3/16 to 5/8 inch forthose with slanted slots. FIG. 24 shows a general purpose spraycontroller 10 bonded to the inside of the fender of a cab ahead of andcentered at the height of the front tire 70 of the tractor 3 where thethrow strikes at nearly normal incidence.

A gutter 205A formed separately and attached, or formed as an integralpart of this general purpose spray controller, as with the floor sillspray controller of FIG. 20, may be used to guide the water from thespray suppressing and coalescing surface 301 to fall at least in part inthe relatively quiescent air inside the paths of the rotating tires.

The slanted slot version having symmetric or asymmetric wedges andhorizontal ribs behind, running across the controller between the slotends, will allow water to flow between the ribs to fall largely beyondthe wheels. This flow is enhanced by providing a slight tilt, downwardtoward the vehicle centerline, when mounting.

Frequently trucks have vertical surfaces ahead of single or dual tiresin which the same embodiment can be applied, with or without gutter. Anysurface exposed to the high speed throw from wet tires may be soprotected by general purpose spray controllers designed with adequateheight, width and gutter cross section. Such a spray controller with amore rigid base is shown ahead of the lead tractor tandem in FIG. 1. Itis used to protect the driver's mirror and can be extended downward forgeneral spray control. It has a gutter 205A below.

The Side Skirt Spray Controller of the Vehicle Spray Control SystemApparatus

Illustrated in FIGS. 6, 7, and 25, the side skirt spray controllers 6are positioned outside the tracks of the tires, being suspended from thevehicle adjacent to the tops of the tires 11 with the base 2 beingparallel to the plane of rotation of the tires 11. In the embodimentshown in FIG. 25A the bisectors of the sloping faces 31 of the wedges 13are positioned perpendicularly to the plane of rotation of the tires tocoalesce mist which has been formed by throw impacting the underbody ofthe vehicle over the tires at high velocity. Mist continually flowsoutwardly and inwardly, with the outward flow partially impacting theside skirt, but much flowing laterally under the side skirt. Arrays ofvertically oriented wedges above the gutter may be closely spaced apart,abutting, or widely spaced apart, but preferably have slanted slotsbetween closely spaced apart wedges 13 in FIG. 5A or 13A in FIG. 35 thatface rearward so the airflow outside the side skirt draws the mistthrough the slots, enhancing the condensation and reducing the flow ofmist under the skirt. Water flows downward between the wedges and downthe outer surface to the gutter 205 below to be carried rearward to fallthe fender flap.

In the embodiment shown in FIG. 25B, wedges 13A in FIGS. 6 and 25B, orridges 13B in FIGS. 25C and 7, have nearly horizontal upper surfaces.Mist impacting the side skirt and wedges or ridges then coalesces and inpart flows down to the upper horizontal surfaces of the wedges or ridgesand thence rearwardly driven by air motion to fall off the skirt at thelocation of to the fender flap, the larger amount of water falling tothe road surface behind the fender flap, because of the differentialpressure being lower behind the fender flap than ahead of the fenderflap. Flexible side skirts on the side of the vehicle facing into astorm's crosswind deflect slightly inward making gutters of ridges orwedges on these upwind side skirts. Spaced apart ridges or wedges orabutting wedges are used. However, in respect to these side skirt spraycontrollers the wedge angle is not as important. However, the wedgesmust provide adequate surface to carry the water and adequate strengthfor durability. Also the may be larger spacing between wedges or ridgesone half to two inches. The side skirt spray controllers 6 in FIG. 25are secured to the trailer 5 with quick disconnect fittings 19, whichfurther comprise locking arms 24 and hooks 25. The locking arm 24 ispivotally secured to the trailer 5 underbody to be rotatably movedupward when the side skirt spray controllers 6 are being installed orremoved as shown in FIG. 25. The locking arms 24 also secure the sideskirt spray controllers 6 in place. In the preferred embodiment, theside skirt spray controllers 6 have horizontally positioned wedges 34with horizontal upper surfaces 31A without slots.

Tests have shown that a large percentage of spray thrown by the rotatingtires of the moving vehicles is generated by the impact of the waterdroplets above the wheels and tires. Side skirt spray controllers 6 maybe even more effective in controlling road surface spray than the moreconventionally placed fender flap spray controllers 1 and need be onlyapproximately six to eight inches in height to provide an effectivesurface area to suppress and coalesce the mist deflected to the sides ofthe tires. Combined with overwheel spray controllers 47A they would besuperb. Some very effective overwheel spray controllers may eliminatethe need for side skirts, especially at the front corners of trailers.

Some professionals are convinced that a single smooth surface coalescesthis mist as effectively as a textured surface. however, review of testdata seems to show that, in a cross wind, water falling from the bottomsof skirts is blown against the tires causing additional secondary spray.Thus, a gutter shown in FIG. 25A or horizontal wedges shown in FIG. 6,or horizontal ribs shown in FIG. 7, the latter two having nearhorizontal top surfaces, are provided to carry the coalesced waterrearwardly especially on the upwind side to fall at the fender flap awayfrom the high speed tread. The experimental symmetrical horizontalwedges had 1/16 inch wide by 3/4 inch long slots between and were madeof neoprene which wets with water. Non-wetting surfaces may be lesseffective. The experimental device is shown in FIG. 25D.

This experimental wedge was very effective even though the 17 1/2 degreeupper surface sloped downwardly. The effect was actually unexpected, butthe wind from the vehicle's speed blew the water rearwardly as it slowlyflowed downwardly across the wedges. Horizontal upper surfaces will makethem even more effective, especially on the side of the vehicle facinginto the storm's cross wind which bends the flexible skirt inwardconverting the upper surfaces into gutters, but the coalescence andrearward motion of water along the wedges continues on skirts on thevehicle's side facing away from the storm's cross wind as the skirtsbend outwardly and the wedge upper surfaces tilt downwardly, thecoalesced water cleaning them as it flows downwardly and rearwardly overthe wedges, blown also by the air flow from the vehicle's speed, beforefalling away from the tire in the cross wind.

Tire Throw Angle Coverage by Overwheel and Floor Sill Spray ControllersCompared to That by Fender Flap Spray Controllers

FIGS. 26A tractor 3, and 26B trailer 5, illustrate the comparative anglecoverage by various spray controllers. In FIG. 26A spray thrown fromtires in angular intervals 71, 72, 74 and 76 impinges on fender flapspray controller 1B, overwheel spray controller 7 and floor sill spraycontroller 9, respectively. The 30 inch long fender flap spraycontroller 1B intercepts 39 degrees of throw between directions 91 and92. The 26 inch width of the base 2 of the overwheel 7 and floor sill 9spray controllers intercept 57 degrees of throw between directions 93and 94, between 94 and 96, and between 97 and 98. Although it variesamong vehicles, approximately 46 percent greater angle coverage of tirethrow is obtained with only 87 percent as much area giving about 68percent greater angle coverage per unit weight of material of theoverwheel spray controller than by the fender flap spray controller 1.In FIG. 26B the same fender flap spray controller 1, because of itstypical location on a trailer, gives a coverage of only 29 1/2 degrees.The overwheel spray controller 7 and floor sill controller 9 combine togive 70 degree coverage with only 73 percent as much area for a 137percent improvement compared to the fender flap spray controller 1 perunit weight of material. This coverage is reduced because the front andrear edges must be moved farther from tire centers as the wedge heightincreases in order to protect the controller from tire impact. Wedgeheights greater than 5/8 inch are certainly undesirable, 7/16 inch isexcellent on the basis of tests, but the 1/4 inch asymmetric wedgeheight with 35 degree slots, gives manufacturing advantages, is almostas effective, and can end closer to the overwheel projection of theaxle.

A combination of several embodiments of spray controllers 27 usedtogether provides a more effective means to suppress and control spray.These examples also demonstrate significant improvement in spray controlby positioning the spray controllers properly, such as by placing thefender flap spray controller 1 low and close to the tires of thevehicle. If the latter fender flap spray controllers 1 were simplylowered to approximately five inches off the ground, their angularcoverage would be more than doubled to 62 1/2 degrees. FIG. 27 shows afender flap hung at an angle to improve the efficiency of spraysuppression per unit length of fender flap. It, together with anoverwheel spray controller is believed to provide excellent spraycontrol, and addition of a floor sill spray controller makes coverageover the wheel fairly complete, perhaps eliminating the need for sideskirts. A fender flap hung further behind a wheel provides lessvariation in the smallest angle of throw from the loaded to the unloadedvehicle. This advantage conflicts with the advantage of greater anglecoverage when close to the wheel, unless the flap is hung from a fittingthat moves up and down with the axle.

Light Weight Flexible Hangers Protect the Fender Flap Spray Controllersof the Vehicle Spray Control System Apparatus

FIG. 29 shows a lightweight flexible hanger 99 to reduce fender flapspray controller 1 damage by drivers backing into loading docks forexample. A spring steel angular member 102 is attached to the underbodyof the trailer behind a wheel, to an I beam, channel or to the frame ofthe trailer 5 by bolts 100 or welding 101. The extended section 104provides resilience to allow flexing. Quick-connect, quick-disconnectcapability is provided by the hook 106 and the snap-tight projection108. Spring action for the snap-tight projection 108 is provided byintermediate section 110. To install the fender flap spray controller 1the top holes 111 in the flap go over the hooks 106 which pass throughthe fender flap spray controller 1, FIG. 28. The fender flap spraycontroller is then bent down into the vertical position, or to theslanted position FIG. 27, and the snap-tight projections 108 protrudethrough holes 112 in the fender flap spray controller 1. The snap-tightprojections 108 have lower lips 114 which snap into place as the bottomof the fender flap spray controller is pressed forward, holding itsecure, locking it in place and providing the anti-sail function for theflap. On removal the snap-tight projections are pressed upward todisengage the fender flap. Section 110 can be angled down aft to suspendthe flap as in FIG. 27.

Manufacture of Spray Controllers Includes the Use of Plastic and TwoTypes of Rubber Including Fiber and New Rubber

The various embodiments of spray controllers 27 can be made by usingplastic, metal and/or new rubber compound, in extruding simple wedge 13arrays, without slots 15, or in a compression or injection moldingprocess forming embodiments with or without slots. A two-step process offirst molding or extruding, then cutting out the slots, may also beused. Fiber, scrap rubber from the manufacture of tires, may also beused as the primary material, mixed with appropriate portions ofcompound, to minimize cost. However, high or low density polyethylene isbelieved to be superior in most embodiments.

SUMMARY OF ADVANTAGES

The primary embodiments of this vehicle spray control system consist ofspray controllers 27 comprising arrays of sloping faced wedges 13 and13A or ridges 13B projecting from the planar surface 30 of the base 2with unperforated base as shown in FIGS. 2 and 3, straight slots 15A, asshown in FIG. 4, or slanted slots 15 shown in FIGS. 5A, 5B, 34 and 35between the wedges 13 and 13A to suppress the formation of spray, and tocoalesce secondary spray, the resulting water then flowing down thereceiving side of the controller, passing through the controller,coalescing and being deflected while passing through the controller tothereafter fall in part outside the tracks of the tires 11 or flowingalong ridges or wedges having horizontal upper surfaces to fall fenderflap. The spray controllers of the system are positioned ahead of,behind, over and beside tires on vehicles 4 to coalesce spray or throwand/or suppress the formation of mist and spray that otherwiseoriginates from the impact of high velocity water droplets on hard flatsurfaces. The components of this spray control system provide excellentspray control by applying nine physical principles: First, collisionenergy of a droplet with a plane surface and, therefore, the amount ofspray that it generates upon impact is dependent upon its speed and uponits direction of motion relative to that surface, decreasingcontinuously from a maximum at normal incidence to essentially zero at adirection essentially parallel to that surface. Second, spray or mistdroplets condense more rapidly to form larger droplets of water as theirconcentration increases by compression or by glancing incidence upon awet surface. Third, collected water per unit cross section in a straightslot to block direct non-impact passage of throw increases with wedgeangle, wedge height and base thickness and with decreasing slot width.Fourth, effectiveness of spray suppression is proportional to thepercent of effective wedge and slot area available for suppression notcovered by accumulated water. Fifth, increasing slot width increases theflow rate of water through the slots for heavy throw rates reducingaccumulated water, and thereby reducing spray generated bythrow-on-water impacts. Sixth, for a given wedge angle and basethickness the ratio of wedge separation to wedge width must remainconstant to maintain a given level of spray control. Seventh, throwstriking a wedge array with slots passes through the slots moreefficiently as the flow distance along the wedge surface decreases byapproaching a normally incident impact angle to the array and as thewedge height decreases. Eighth, the effectiveness of a slotted array isincreased as the end to end longitudinal separation of slots decreasesas a percent of slot length. Ninth, side skirts having horizontal wedgesreduce the amount of water falling directly downward beside the wheelsthat, in a storm's side wind, blows onto the upwind tires, and alsoreduces the amount of water caught in the upwind ahead of the fenderflap caused by tire rotation by carrying a significant amount of waterto fall from top skirt at the fender flap location, a large amount ofwater falling to the road surface behind the fender flap, because of thedifferential pressure being lower behind the fender flap than ahead ofthe fender flap.

Minimum usage of only the fender flap spray controllers 1 using wedgearrays illustrated in FIGS. 2, 3, and 4 and side skirts of this designeffectively control only somewhat more than 30 percent of the throwangle. However, spray conditions on occasions are severe enough thatthis minimum usage does not provide adequate safety because abouttwo-thirds of the throw angle is over the wheels and in other positions.On these occasions, which may be addressed by upcoming Federalstandards, use of additional embodiments will reduce time lost toweather and help to avoid costly accidents.

Overwheel spray controllers 7, shown in FIGS. 1, 12, 13, 26A, 26B and 30to 41, and floor sill spray controllers 9 in FIGS. 19A and 20 willeffectively control much of the 60 percent of throw angle over thetires. Over the region between tandem axles the overwheel spraycontroller alone, that is without the between tractor tandem spraycontrollers, is expected to achieve good spray control because the heavythrow from the front tandem will sweep much of the very fine mist,formed by tire to tire throw impacts, upward with it to the overwheelspray controllers above as illustrated over the trailer tandems in FIG.1.

Supplementing the above is the between tractor tandem spray controller12 which, if owners can be persuaded to use it, will give even bettercontrol of the spray formed between tandems. The combined system hasexperimentally been demonstrated to provide excellent spray control.

General purpose spray controllers 10, with gutters below, or withslanted slots and horizontal ribs behind, as with the floor sillcontroller of FIG. 19A, can be used to suppress and coalesce the throw,the gutters, if present, or wedges and slanted slots directing theresulting water between the ribs to fall inside the tires in therelatively quiescent dragged air. They are best used bonded to the endsof fuel tanks, to the insides of fenders in regions that receive throwthat impacts essentially normal to the surface, and as shields set up tointercept, coalesce, suppress and divert throw which would otherwiseimpact the tractor mirrors, the chain storage or any other surface thatwould convert the high speed throw to mist.

Thus, these innovations complete the protection, providing the greatestnumber of driving hours and the greatest safety under the widely variedweather conditions encountered on the highways of the world.

I claim:
 1. A vehicle spray control system apparatus to directly receivewater thrown from rotating tires of vehicles, hereinafter referred tosimply as "throw" throughout all the claims, via centrifugal forces,during the travel of vehicles over wet surfaces, comprising:a) a spraycontroller, in turn comprising an unperforated base, and a plurality ofparallel wedges integrally formed with and projecting from the base,each wedge having: a wedge base which is common with the base of thespray controller; sloping sides extending from the wedge base to createa continuous apex edge having throughout an included angle which is inthe range of at least 30 but no more than 40 degrees; an apex heightabove the wedge base which is in the range of at least 9/32 but no morethan 15/32 of an inch; a separation between bases of adjacent wedges nomore than 37% of the width of the wedge bases; and b) means to securethe spray controller to a vehicle, so the continuous apex edges of theparallel wedges are directed toward a rotating tire of a vehicle, thevertices of the wedges lying in the planes of rotation of the tire andparallel thereto.
 2. A vehicle spray control system apparatus as claimedin claim 1, wherein the spray controller is suspended vertically betweena forward and a rear tire which are aligned and mounted between wheelssecured to tandem axles and below an overwheel spray controller, whichcoalesces, suppresses and deflects upward-moving throw to fall beyondthe tire treads, and the lower portion of the vertical spray controllerhas closely spaced apart wedges extending toward the forward tire, theupper portion of the forward surface having no wedges; and the upperportion of the spray controller has abutting wedges extending toward therear tire, the lower rearward facing surface being devoid of wedges, andwhich is securely held in position to prevent forward and rearwardmovement that would allow it to strike the tires.
 3. A vehicle spraycontrol system apparatus, as claimed in claim 1, comprising a spraycontroller, called a floor sill spray controller, which is adaptablysupported on the rear vertical surface of a floor sill structure supportmember extending transversely beneath the vehicle with the wedge arrayvertical, apexes facing rearward to receive the forward-moving throwfrom the top of the tire.
 4. A vehicle spray control system apparatus,as claimed in claim 3, comprising in addition a transverse gutter toreceive the water collected by the floor sill spray controller anddirect the collected water toward the center of the vehicle for drainageonto the wet surface below.
 5. A vehicle spray control system apparatusas in claim 1, called a general purpose spray controller, in which thematerial of construction is flexible and the thickness of the base, upto 1/4 inch, is selected to provide adequate flexibility to bond tocurved surfaces such as the ends of the fuel tank and inside of thefront fender and so mounted to intercept, coalesce and suppress thethrow from a tire directly.
 6. A vehicle spray control system apparatusas in claim 1 in which the material of construction is selected toprovide rigidity for use as a shield, mounted ahead of and above aforward tandem and having an integral gutter, wedges facing rearward anddownward and aligned with the rotation planes of the tires, and thegutter draining inward with water falling inside the tires.
 7. A vehiclespray control system apparatus as in claim 1 in which the spraycontroller is rigidly mounted by a supporting structure.
 8. A vehiclespray control system apparatus as defined in claim 1 which is formed asa fender flap and which is adaptably supported being a vehicle wheel,bottom sloping rearward at a range of angles with the vertical up to 30degrees.
 9. A vehicle spray control system apparatus to receive waterthrown from rotating tires of vehicles, via centrifugal forces, duringthe travel of vehicles over wet surfaces, comprising:a) a spraycontroller, in turn comprising a base which is in the range of 3/32 to5/16 inch in thickness, having spaced slots of transverse width in therange of 1/32 to 3/32 inch and of a longitudinal length at least 1/2inch with the longitudinal spacing between slots being less than 35percent of the slot length with the slots extending perpendicularlythrough the base, and a plurality of spaced parallel symmetric wedgesintegrally formed with and projecting from the base longitudinallybetween the spaced slots, each wedge having: a wedge base which iscommon with the base of the spray controller, with the width of thewedge base being wide enough so the wedge bases are spaced apart oneither side of the spaced slots of the base at a distance, equal to theslot width, which is 22 percent or less of the respective width of thewedge bases; sloping sides extending from and contiguous to the slotedges in the controller base to create a continuous apex edge havingthroughout an included angle of at least 40 degrees; and an apex edgeheight above the wedge base, which is in the range of 7/32 to 15/32inch; and b) means to secure the spray controller to a vehicle, so thecontinuous apex edges of the parallel wedges are directed toward arotating tire of a vehicle, whereby the planes of symmetry of the wedgesare parallel to the planes of rotation of the tire.
 10. A vehicle spraycontrol system apparatus for suppressing spray and preventing theformation of mist by coalescing and redirecting water droplets fromtread throw which has been thrown upwardly or rearwardly by the rotatingtires of a vehicle via centrifugal forces of the rotational movement ofthe tires during travel of the vehicle along wet surfaces or roadways,comprising spray controllers, having a receiving side and an oppositeside, and which each further comprise:a) a base having a plurality ofelongated slots longitudinally positioned and spaced apart, extendingthrough the base angularly forming a slanted aperture through whichdroplets of spray pass, such droplets being suppressed upon strikingwedge sloping faces and slanted surfaces of the slots and therebydirected away in part from the path of the rotating tires of thevehicle; and b) a plurality of edges with apex angles of 60 degrees orless having opposite symmetrical sloping faces symmetrically orientedtoward oncoming droplets of spray wherein the wedges depend outwardlyfrom the base toward the direction of spray and are positioned adjacentto the slots whereby a slanted surface of each slot is preferably acontinuation of and integral with a sloping face of the adjacent wedge,the wedges thereby providing surface area to receive the impact of thespray water droplets thereafter suppressing and coalescing the spraydroplets into larger droplets and a flow of water which is stream-likein appearance.
 11. A vehicle spray control system apparatus as definedin claim 10 wherein the slots of the spray controllers are adaptablyoriented within the base whereby, with respect to a longitudinalcenterline of the vehicle tires, half of the slots are slanted in onedirection, in parallel alignment, away from said centerline while theother half of the slots are slanted symmetrically away, in parallelalignment, from and on the opposite side of said centerline to therebyguide the flow of the now suppressed and coalesced spray to therespectively divergent halves of the spray controller and thusredirecting the flow of water droplets through the base to thereafter bedischarged from the opposite side of the spray controller away from thecenter of the spray controller and in part away from the path of therotating wheels and tires of the vehicle.
 12. A vehicle spray controlsystem apparatus as defined in claim 10 wherein the slots are allslanted in the same direction in parallel alignment, extending troughthe base at an angle so as to discharge the water droplets from theopposite side of the spray controller laterally in one direction.
 13. Avehicle spray control system apparatus, as claimed in claim 10,comprising, in addition, another spray controller, called a side skirt,which is positioned vertically beyond the vertical plane projection of atire, having a base, having wedges preferably vertically orientedextending from the base toward the tire, having the bisector of thesloping faces of the wedges extending perpendicularly to the plane ofrotation of a tire, and having the slanted slots oriented to directoutgoing air and water toward the rear.
 14. A vehicle spray controlsystem apparatus as claimed in claim 12 comprising, in addition, anotherspray controller, called an overwheel spray controller, which isarranged almost horizontally in the vertical plane projection of a tire,having the wedges and slanted slots arranged to suppress, coalesce anddeflect the water from the throw via the slanted slots toward the centerof the vehicle over the spray controller after their impacting, on theoverwheel spray controller above the rear of a tire, or above andbetween tandems, the resulting water falling clear of the tire and clearof following tires to the wet roadway in relatively quiescent airdragged along with the vehicle, and having barriers preventing waterflow off the front and outside edges of this overwheel spray controller.15. A vehicle spray controller system apparatus as defined in claim 12wherein the spray controller is adaptably supported on the rear verticalsurface of a floor sill structural support member, extendingtransversely beneath the vehicle wherein a plurality of ribs are securedhorizontally to the back of the base, being spaced apart and positionedtransversely to the wedges and slots so as to permit runoff beyond thepaths of the rotating tires toward the center of the vehicle of thecoalesced and suppressed spray which has thereafter become a flow ofwater stream-like in appearance upon striking and then passing throughthe spray controller.
 16. A spray control system apparatus as in claimsnumbers 1, 9, or 10 having the base under the wedge hollowed out so thematerial thickness is optimized, for speed of molding and yet retainadequate strength for the application.
 17. A spray control systemapparatus as in claim 1 or 9 and having means to secure the saidapparatus to a vehicle to serve as a fender flap positioned behind thewheels of tractors, trailers, trucks, automobiles and aircraft tocontrol spray thrown from tires running on wet roadways and runways. 18.A spray control system apparatus as in claim 17 in which the baseopposite the edges is hollowed out to optimize the wall thickness,dependent on material, for speed of molding yet retain adquate strength.19. A vehicle spray control system apparatus as claimed in claim 14,this overwheel spray controller with rear barrier being positioned at aslight downward slope toward the vehicle centerline to direct water flowtoward the center of the vehicle.
 20. A vehicle spray control systemapparatus as claimed in claim 15 with rear barrier in which longitudinalstrips of the base at the center and at the inner edge of this overwheelspray controller are devoid of slots and wedges over the space betweentires that receives little throw when installed over duals, the innerportion of the base sloping downward to an inner barrier which hasopenings at the front and rear, the barrier forming the inner edge of agutter and the openings allowing the water to stream toward the roadsurface clear of the tire path.
 21. A vehicle spray control systemapparatus as claimed in claim 13 with a gutter below to carry waterrearwardly to fall behind the wheel.
 22. A vehicle spray control systemapparatus as in claim 11, positioned horizontally to receive the upwardmoving throw from tires and having strips along the inner and outer edgedevoid of slots and wedges extending fore and aft which edge strips tiltdownward respectively toward the center and toward the side of thevehicle, having barrier walls above each of the four edges to preventflow off the top of the controller except that the inner and outerbarrier walls have narrow openings both fore and aft to allow water toflow in a stream off the controller beyond the tires.
 23. A vehiclespray control system apparatus, as claimed in claim 10, in which theslope of the slot, as measured from vertical to the base surface, isgreater than the slope of the side of the wedge, thereby causing theflow of water exiting from the base to be more nearly parallel to thebase surface, the slot edges at their intersections with the edge basesremaining contiguous to the wedge bases.
 24. A vehicle spray controlsystem apparatus for suppressing spray and preventing the formation ofmist by coalescing and redirecting water droplets from tread throw whichhas been thrown upwardly, rearwardly, or forwardly by the rotating tiresof a vehicle via centrifugal forces of the rotational movement of thetires during travel of the vehicle along wet surfaces or roadways,comprising spray controllers, having a receiving side and an oppositeside, and which each further comprise:a) a base having a plurality ofelongated slots longitudinally positioned and spaced apart, extendingthrough the base angularly forming a slanted aperture through whichdroplets of spray pass, such droplets being suppressed upon strikingwedge sloping faces and slanted surfaces of the slots and therebydirected away in part from the path of the rotating tires of thevehicle; and b) a plurality of wedges with apex angles of 45 degrees orless having one side substantially perpendicular to the base and theother side sloped at an angle in the range of 15 to 45 degrees, havingthe vertices oriented toward oncoming droplets of spray wherein thewedges depend outwardly from the base toward the direction of spray andare positioned adjacent to the slots whereby a slanted surface of eachsot is preferably a continuation of and integral with a sloping face ofthe adjacent wedge, the wedges thereby providing surface area to receivethe impact of the spray water droplets thereafter suppressing andcoalescing the spray droplets into larger droplets and a flow of waterwhich is stream-like in appearance.
 25. A vehicle spray control systemapparatus as defined in claim 24 wherein the slots of the spraycontrollers are adaptably oriented within the base whereby, with respectto a longitudinal one direction, in parallel alignment, away from saidcenterline while the other half of the slots are slanted symmetricallyaway, in parallel alignment, from and on the opposite side of saidcenterline to thereby guide the flow of the now suppressed and coalescedspray to the respectively divergent halves of the spray controller andthus redirecting the flow of water droplets through the base tothereafter be discharged from the opposite side of the spray controlleraway from the center of the spray controller and in part away from thepath of the rotating wheels and tires of the vehicle.
 26. A vehiclespray control system apparatus as defined in claim 24 wherein the slotsare all slanted in the same direction in parallel alignment, extendingthrough the base at an angle so as to discharge the water droplets fromthe opposite side of the spray controller laterally in one direction.27. A vehicle spray control system apparatus, as claimed in claim 26,comprising, in addition, another spray controller, called a side skirt,which is positioned vertically beyond the vertical plane projection of atire, having a base, having wedges vertically oriented extending fromthe base toward the tire, and having the slanted slots oriented todirect outgoing air and water toward the rear.
 28. A vehicle spraycontrol system apparatus as claimed in claim 26, comprising, inaddition, another spray controller, called an overwheel spraycontroller, which is arranged substantially horizontally in the verticalplane projection of a tire, having the wedges and slanted slots arrangedto suppress, coalesce and deflect the water from the throw via theslanted slots toward the center of the vehicle over the spray controllerafter their impacting, on the overwheel spray controller above the rearof a tire, or above and between tandems, the resulting water fallingclear of the tire and clear of following tires to the wet roadway inrelatively quiescent air dragged along with the vehicle, and havingbarriers preventing water flow off the front and outside edges of thisoverwheel spray controller.
 29. A vehicle spray control system apparatusas claimed in claim 28, this overwheel spray controller with rearbarrier being positioned at a slight downward slope toward the vehiclecenterline to direct water flow toward the center of the vehicle, andhaving an inner longitudinal strip devoid of slots and wedges whichtilts down to an inner barrier with openings fore and aft.
 30. A vehiclespray control system apparatus as claimed in claim 29 in whichlongitudinal strips of the base at the center and at the inner edge ofthis overwheel spray controller are devoid of slots and wedges over thespace between tires that receives little throw when installed overduals, the inner portion of the base sloping downward to an innerbarrier, which has openings at the front and rear, the barrier formingthe inner edge of a gutter and the openings allowing the water to streamoutward toward the road surface clear of the tire path.
 31. A vehiclespray control system apparatus as in claim 27 having an integral gutterat the lower edge of the side skirt that is designed to carry thecoalesced and suppressed water to fall in proximity to a fender flap, avertical spray controller behind a wheel.
 32. A vehicle spray controlsystem apparatus called a general purpose spray controller designed asin claim 26 in which ribs on the back surface run perpendicular to theslots and between the sots providing a means to bond the apparatus madeof a flexible material to a surface impacted directly by throw such asthe ends of fuel tanks or the fender ahead of a tire and allow thesuppressed and coalesced water to flow behind the controller to fall atleast in part inside the tires of the vehicle.
 33. A vehicle spraycontrol system apparatus called a between tractor tandem spraycontroller, as claimed in claim 25, wherein the spray controller issuspended vertically between a forward tire and a rear tire, which arealigned, and mounted between wheels secured to tandem axles, and belowan overwheel spray controller designed to coalesce, suppress and deflectthe upcoming throw beyond the tires and located over the rear of thefront tandem extending to this between tractor tandem spray controller,and the lower portion of the spray controller has asymmetric wedgesextending toward the forward tire but is devoid of wedges on itsrearward surface, and the upper portion of the spray controller hasasymmetric wedges extending toward the rear tire but is devoid of wedgeson its forward surface, and which is securely held in position toprevent forward and rearward movement that would allow it to strike thetires, and which deflects symmetrically half of the efflux from theslots, both top and bottom, toward the left and the other half of theefflux, toward the right, a substantial amount falling outside thetracks of the vehicle.
 34. A vehicle spray control system apparatus asclaimed in claim 25 positioned horizontally to receive the upward movingthrow from tires, having strips, devoid of slots and wedges, extendingfore and aft, centered along the longitudinal centerline, another alongthe inner edge and the third along the outer edge, where little throwimpinges when installed over duals, barriers along the four edges, bothinner and outer barriers having openings fore and aft, and the inner andouter strips sloping downward to their respective barriers.
 35. Avehicle spray control system apparatus as claimed in claim 30 in whichthis overwheel spray controller may be made long enough to extend frombehind the center of a forward tractor tandem tire when the fifth wheel,used to adjust the trailer position fore and aft, is in its furthestrearward position and rearward to the fender flap position, the fenderflap being attached to the trailer frame, behind the rear tandem, whenthe fifth wheel is in its most forward position, and is attached to thesurface over the tractor tandem positions.
 36. A vehicle spray controlsystem apparatus as in claim 27 in which this overwheel spraycontroller, attached to the trailer, is made long enough to extend frombehind the center of the forward tractor tandem tire when the fifthwheel, which adjusts the fore and aft position of the trailer reactiveto the tractor, is in its most rearward position, rearward to thetractor-mounted fender flap location behind the rear tandem, relative tothe trailer, when the fifth wheel is in its most forward position, andis attached to the surface over the tractor tandem positions.
 37. Avehicle spray control system apparatus as in claim 26 made of a rigidmaterial and mounted ahead of and above a forward tractor tandem so itmay be used as a shield to protect the rear view mirrors from throw. 38.A vehicle spray control system apparatus as in claim 26 in which thespray controller is rigidly mounted by a supporting structure.
 39. Avehicle spray control system apparatus, as claimed in claims 14, 28, 27,or 22, this overwheel spray controller being positioned at a slightdownward slope aft to direct more of the water to flow rearward to fallnearer the fender flap.